Grounding bushing



FIG. 1 is a top perspective view of a grounding bushing embodying my new design;

FIG. 2 is a bottom perspective view thereof;

FIG. 3 is a top view thereof;

FIG. 4 is a side view thereof, the opposite side view being a mirror image thereof; and

FIG. 5 is a bottom view thereof. 

The ornamental design for a grounding bushing, substantially as shown and described. 